RAC2 and melanoma: To further support the role for Rac2 and macrophage autonomy in the control of metastasis, we performed simultaneous local injections of WT BMDMs into right hemithorax of Rac2-/- vs. injection of WT GBMDMs into the left hemithorax of the same Rac2-/- mouse, followed by B16F10 melanoma tail vein injections two days later.